Photo flash lamps currently comprise in general lamps typically filled with an oxidizer, i.e., a gas that supports combustion such as oxygen and a combustible, such as aluminum-magnesium alloy or aluminum, magnesium or zirconium. Such flash lamps typically comprise hermetically sealed light transmitting glass envelopes which contain a filamentary combustible material, such as shredded aluminum or shredded zirconium foil immersed in a combustion supporting gas, such as oxygen.
In battery operated photo flash lamps, an electrical ignition system is included within the envelope of the lamp comprising a tungsten filament supported on a pair of lead-in wires having a quantity of ignition paste on the inner ends thereof adjacent to the filament. This type of lamp is operated by the passage of electric current through the lead-in wires. (See, for example, U.S. Pat. No. 3,895,902 issued July 22, 1975 to Broadt et al. entitled "Photo Flash Lamp".)
Another type of photo flash lamp comprises the percussive type, such as described in U.S. Pat. No. 3,535,063 which includes a mechanically activated primer sealed in one end of the lamp envelope. The ignition system may comprise a metal tube extending from the lamp envelope and a charge of fulminating material on a wire supported in the tube. Operation of the percussive photo flash lamp is initiated by an impact onto the tube to cause deflagration of the fulminating material up through the tube to ignite the combustible disposed in the lamp envelope.
Another type of photo flash lamp is the piezo-electric ignited flash lamp in which a high voltage in the neighborhood of 2,000 Volts is produced by a piezo-electric device to cause a spark to be emitted which ignites the combustible material, i.e, the primer within the lamp envelope. This is contrasted with battery ignited-type photo flash lamp which utilizes a relatively high current in the neighborhood of amperes to ignite the combustible.
All of these igniter systems for the shredded combustible photo flash lamps suffer from the problem that a significant delay exists between the time the igniter is enabled and the photo flash occurs. A need exists for flash lamps which create a substantially rapid and simultaneous ignition of the combustible.
One advantage for such a flash lamp in photo applications, would be to avoid the necessity of delaying shutter opening until a fixed time after the lamp is ignited. Present photo flash lamps require an "M synchronization" setting for this purpose.